Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 c04016dfa9b5eb57…

MALICIOUS

RTF / .DOC

2.14 MB First seen: 2021-10-07
MD5: 7b4fc68118dd4f343598987595c32a0b SHA-1: 3e08e797bbd3894fe52608a7214448d94421a672 SHA-256: c04016dfa9b5eb5735d31672b9313c29f3d8661bdf42b609b7552e428742f9a8
180 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.003 Windows Command Shell

The RTF document contains embedded OLE objects, specifically triggering the CVE-2017-11882 Equation Editor vulnerability. The presence of objupdate indicates that the embedded object is forced to activate, leading to arbitrary code execution. This is a common delivery mechanism for exploiting known vulnerabilities in Microsoft Office components.

Heuristics 5

  • Equation Editor activation — CVE-2017-11882 related high CVE related CVE_2017_11882_ACTIVATION_RELATED
    RTF decodes to an Equation.3 ProgID and requests OLE activation with \objemb plus \objupdate. This reaches the legacy Equation Editor attack surface used by CVE-2017-11882/CVE-2018-0802 documents, but the malformed MTEF/native payload needed for stronger attribution was not recovered.
  • Split hex Equation Editor ProgID + OLE object critical RTF_EQUATION_EDITOR
    RTF embeds the Equation.3 ProgID as hex bytes near OLE object activation and splits the byte stream with whitespace or an ignorable RTF group. This is an Equation Editor OLE activation surface commonly used by CVE-2017-11882 / CVE-2018-0802 exploit documents.
  • \objupdate forces OLE activation high RTF_OBJUPDATE
    RTF contains \objupdate — forces automatic OLE object instantiation when the document is opened, bypassing user interaction. Almost exclusively seen in Equation Editor exploit documents.
  • OLE object data medium RTF_OBJDATA
    RTF contains 2 \objdata section(s) — embedded OLE objects
  • Embedded OLE object medium RTF_OBJEMB
    RTF contains \objemb — embedded OLE object

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off000011e1.bin
2d201b362dde549a7ab5c91293a4f431e0dfa87332339f1c5fd69bc2bf16b03a		 rtf-objdata-decoded RTF \objdata at offset 0x11E1 28759 bytes
objdata_01_off000195c1.bin
c871b0ddd22fecfdd6e974f8c3ec280f048875d55c366cef5086c24bb2763af3		 rtf-objdata-decoded RTF \objdata at offset 0x195C1 546134 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.